knee-jerk
[nee-jurk]
- of or relating to a knee-jerk.
- Informal. reacting according to a certain habitual manner; unthinking: a knee-jerk liberal.
Origin of knee-jerk
First recorded in 1895–1900
knee jerk
- a reflex extension of the leg, caused by contraction of the quadriceps, resulting from a sharp tap on the patellar tendon; patellar reflex.
Origin of knee jerk
First recorded in 1875–80
Dictionary.com Unabridged
Based on the Random House Unabridged Dictionary, © Random House, Inc. 2018
Examples from the Web for knee-jerk
Contemporary Examples
It is not a knee-jerk response to a sudden perceived threat.
This whole thing about a black-and-white culture of knee-jerk reactions is reinforced by television.
The knee-jerk cynicism with which it has been greeted is dysfunctional.
Republicans are going to try to paint Bellows as a knee-jerk Democrat who just uses the civil-liberties argument when convenient.
The passage contradicts the knee-jerk reaction which wants to quantify suffering.
Susan Minot on Africa, Joseph Kony, and the Limits of Writing About LoveLea Carpenter
February 10, 2014
Historical Examples
Sensibility, the knee-jerk, and plantar phenomena are normal.
A Statistical Inquiry Into the Nature and Treatment of EpilepsyAlexander Hughes Bennett
Later the affected muscles become exquisitely tender, and then atrophy, while the knee-jerk or other reflex is lost.
The deep reflexes may also be altered, the knee-jerk being frequently absent on the affected side.
In some subjects the larger dose, 45 cubic centimeters, practically abolished the knee-jerk.
How to LiveIrving Fisher and Eugene Fisk
The presence or absence of the knee-jerk may be a most significant symptom to the physician.
A Practical PhysiologyAlbert F. Blaisdell
knee jerk
- Also called: patellar reflex physiol an outward reflex kick of the lower leg caused by a sharp tap on the quadriceps tendon just below the patella
- made or occurring as a predictable and automatic response, without thoughtkneejerk support
Collins English Dictionary - Complete & Unabridged 2012 Digital Edition
© William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins
Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012
Word Origin and History for knee-jerk
n.
patellar reflex, neurological phenomenon discovered and named 1876; the figurative use appeared soon after the phrase was coined.
Online Etymology Dictionary, © 2010 Douglas Harper
knee jerk
The American Heritage® Stedman's Medical Dictionary
Copyright © 2002, 2001, 1995 by Houghton Mifflin Company. Published by Houghton Mifflin Company.